Location-Based Oncological Outcomes of Sentinel Node Dissection in Radical Prostatectomy

Abstract

Purpose: Our study aimed to assess the oncological outcomes of sentinel node dissection during radical prostatectomy according to nodal location in comparison to extended pelvic lymph node dissection.

Materials and methods: Prospectively collected data of clinically node-negative patients who underwent prostatectomy and extended lymph node dissection with or without sentinel node from January 2013 to January 2023 were retrospectively analyzed. The primary end point was to assess oncological outcomes on the whole population. Kaplan-Meier curves were used to depict biochemical and clinical recurrence-free survival. Multivariable Cox regression models assessed the impact of nodal location on single-photon emission computed tomography on oncological outcomes. Adjustment for case mix included: pathological T stage, ISUP (International Society of Urological Pathology) grade group, initial PSA, nodal burden, age at surgery, and surgical margin status. Secondarily, a propensity score match was performed according to age at surgery, PSA, biopsy ISUP, clinical T stage, and Briganti risk of nodal invasion. Survival and regression analyses were also performed in the matched population.

Results: Of the patients, 55.8% had at least 1 sentinel node outside of lymph node dissection template at single-photon emission computed tomography/CT. Log-rank test showed comparable 36-month biochemical (P = .3) and clinical recurrence-free survival (P = .6) among patients with sentinel node inside template, outside template, or extended pelvic lymph node dissection alone. At Cox regression, sentinel node location outside template was associated with lower hazard of metastases (HR 0.62; P = .04) in the overall cohort, while in the matched cohort benefits were observed only for biochemical recurrence (HR 0.57; P = .001).

Conclusions: Wider nodal resection boundaries outside the "classic" template, driven by sentinel node procedure, have a positive impact on oncological outcomes in selected patient.

Keywords: lymph node dissection; prostate cancer; radical prostatectomy; radioguided; sentinel node.